Yumiko Yamaoka
Kobe Gakuin University
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Featured researches published by Yumiko Yamaoka.
Chemico-Biological Interactions | 2000
Fumiyo Kasuya; Yumiko Yamaoka; Eriko Osawa; Kazuo Igarashi; Miyoshi Fukui
The relative importance of the liver and kidney for glycine conjugation of ortho-substituted benzoic acids was investigated. Glycine conjugation of ortho-substituted benzoic acids was investigated in mouse liver and kidney mitochondria. The extent of glycine conjugation of benzoic acids with the halogen group decreased in the order F > Cl > Br > I. The conjugation of salicylic acid with glycine took place in only the kidney. 2-Methoxybenzoic acid exhibited no activity in the liver and kidney. The difference in glycine conjugation of ortho-substituted benzoic acids was observed between liver and kidney. The kidney was more active in glycine conjugation of ortho-substituted acids than the liver. In addition, the relationship between glycine conjugation and the chemical structure of ortho-substituted acids was examined in the liver and kidney. The size of the substituent had a far greater influence over glycine conjugation in the liver and kidney. Glycine conjugation was also dependent on the substituent electronegativity. It may be important that the substrates undergoing glycine conjugation contain a flat region coplanar to the carboxylate group.
Biochemical Pharmacology | 1998
Fumiyo Kasuya; Yumiko Yamaoka; Kazuo Igarashi; Miyoshi Fukui
Amino acid conjugation is an important route of detoxification of xenobiotic and endogenous carboxylic acids. The specificity of the purified medium chain acyl-CoA synthetase catalyzing the first reaction of amino acid conjugation was investigated further for substrates and inhibitors. Molecular modeling techniques were applied to derive the molecular characteristics of substrates and inhibitors for the medium chain acyl-CoA synthetase. The purified enzyme accepted not only straight medium chain fatty acids but also aromatic acids. Of the arylacetic acids, activity was obtained with naphthylacetic acids, whereas introduction of a methyl group at the alpha-position caused loss of activity. High activity was also observed with cyclohexanoic acid. Diflunisal, 2-hydroxydodecanoic acid, and nalidixic acid inhibited the medium chain acyl-CoA synthetase activity for hexanoic acid, with Ki values of 0.8, 4.4, and 12.3 microM, respectively. The inhibitory carboxylic acids were competitive with respect to hexanoic acid. The hydroxyl or ketone (oxo) groups at the beta-position of carboxylic acids were an important determinant for inhibitory activity. All substrates and inhibitors contained a flat hydrophobic region coplanar to the carboxylate group. In addition, the substrates had negative values for charge on the carbon in the beta-position of carboxylic acids.
Journal of Molecular Spectroscopy | 1980
Yumiko Yamaoka; Katsunosuke Machida
Abstract A simple anharmonic potential containing 18 quadratic, 6 cubic, and 6 quartic constants is proposed to fit 124 vibrational frequencies of 1,1-dichloroethylene and its 37 Cl isotope in the region from 10 000 to 350 cm −1 . The level patterns in the first and the second overtone regions of the CH 2 stretching vibrations are explained by the absence of large higher-order interaction terms between the two CH stretching coordinates.
Journal of Molecular Spectroscopy | 1983
Yumiko Yamaoka; Katsunosuke Machida
Abstract A new and simple method to expand the anharmonic vibrational wave functions with respect to the harmonic oscillator wave functions is proposed. The coefficients of the expansion are given as matrix elements of the S function of the contact transformation in the perturbation theory and the explicit expressions of these coefficients are given within the approximation to the second order in λ. As an example of the expansion, the wave functions of water molecules were calculated and applied to the calculation of infrared band intensities and average values of dipole moments in several states.
Journal of Pharmaceutical Sciences | 1983
Yumiko Yamaoka; Richard Roberts; Valentino J. Stella
Chemical & Pharmaceutical Bulletin | 1982
Atsushi Watanabe; Yumiko Yamaoka; Kozo Takada
Chemical & Pharmaceutical Bulletin | 1992
Yoshikazu Takeuchi; Hidehito Yasukawa; Yumiko Yamaoka; Yuichi Kato; Yasuko Morimoto; Yoshinobu Fukumori; Tomoaki Fukuda
Biological & Pharmaceutical Bulletin | 1998
Yoshikazu Takeuchi; Yumiko Yamaoka; Shoji Fukushima; Kohji Miyawaki; Kenji Taguchi; Hidehito Yasukawa; Syuichi Kishimoto; Masao Suzuki
Chemical & Pharmaceutical Bulletin | 1991
Yoshinobu Fukumori; Hideki Ichikawa; Yumiko Yamaoka; Eiichi Akaho; Yoshikazu Takeuchi; Tomoaki Fukuda; Ryuichi Kanamori; Yoshifumi Osako
Chemical & Pharmaceutical Bulletin | 1980
Ikue Kaneko; Yoshikazu Takeuchi; Yumiko Yamaoka; Tomoaki Fukuda; Yoshinobu Fukumori; Tadanori Mayumi; Takao Hama